Ball bearing



J. B. THOMSON BALL BEARING Nov.` 27, 1951 2 SHEETS-SHEET l Filed Jan.50, 1946 Nov. 27, 1951 J. B. THOMSON BALL BEARING 2 SHEETS- SHEET 2Filed Jan'. 30, 19,46

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' i ATTORNEYS Patented Nov. 27, 1;951

UNITED STATES PATENT OFFICE BALL BEARING John B. Thomson, Plandome, N.Y.

Application January 30, 1946, Serial No. 644,262

4 Claims. l

This invention relates to improvements in the manufacture ofball-bearings whereof the relative movement of the bearing surfaces isone of translation or reciprocation as distinguished from one ofrotation such, for example, as in the case of a shaft longitudinallyslidable `in its bearing or of a bushing slidable along a fixed shaft.

Some of the present improvements are directed to the production ofbearings or bushings of this type which comprise an outer sleeve and aball-cage or ball-retaining means disposed between the sleeve and theshaft to hold and guide the balls in a channel or circuit which theytransverse under operation. One of the problems encountered inthecommercial production of such bearings has to do with the form of, ordesigning of, the interior surface of the sleeve so that the balls inone part of the ballcircuit or circuits will have bearing contact withthe sleeve while the balls in the other or ballreturn parts of thecircuit or circuits will not have bearing contact but will be free tomove in either direction as impelled by the balls having bearingcontact. The particular difficulty in this respect is to design theinterior face of the sleeve in such form that it Will not only serve itsintended purpose, but which form can be readily manufactured by acomparatively simple operation and therefore Without substantialexpense.

The other improvements in slidable bearings which are included hereinare quite independent of the particular character of the ball-retainingmeans and of the form of the inner face of the sleeve, and have to do,in one case, with means for preventing relative rotation between thebearing and shaft and, in another, with means for preventing thebearing-balls from developing grooves in the shaft due to constant wearof the latter along the lines traversed by the balls.

Several embodiments of my improvements are shown in the drawings inwhich Figs. 1 and 2 are views respectively in transverse section andside elevation of one of these embodiments, Figs. 3 and 4 similarrespective views of another embodiment, Fig. 5 a transverse section ofstill another embodiment, Fig. 6 a detail of part of the structure shownin Fig. 5, Fig. Z a detail illustrating a modification of the structureshown in Figs. l and 2, and Figs. 8 and 9 are diagrammatic Views eachillustrative of a particular disposition of the ball circuit or circuitsin relation to the shaft to prevent the wearing of grooves in thelatter.

Referring rst to the embodiment shown in Figs. 1 and 2 wherein the shaftI0 to which the bearing is to be applied is a rounded shaft, the numeralII denotes the outer sleeve of the bearing and the numeral I2 aball-cage Within the sleeve and embracing the shaft. The ball-cage isslotted to form a single continuous ball-race extending around itsperiphery and has axially disposed substantially straight portions I3and curved end portions lli connecting the ends of adjacent straightportions. Such ball-cage may conveniently comprise `two members I5 eachhaving fingers I6 extending into the sleeve from the ends of the latter,thus forming a sinuous ball-race as shown, and which is substantiallyfilled with bearing balls I'I. The ends of the two cage members I5 maybe keyed to the respective ends of the sleeve to maintain the ball-racein its proper operative relation to the inner surface of the sleeve nowto be described.

From Fig. l it will be seen that there is an even number (here shown aseight) of straight portions I3 of the ball-race and that the balls inonly four of these straight portions have bearing contact with the shaftand sleeve; and also that these balls bear upon relatively narrowbearing surfaces I8 extending from end to end of the inner face of thesleeve, and that between these bearing surfaces the inner face of thesleeve is formed with relatively wide arched portions I9 likewiseextending from end to end of the sleeve. And since these bearingsurfaces and arched portions extend from end to end of the sleeve theymay, as will readily appear, be easily and inexpensively formed by asimple operation, such for example as broaching with a suitably adjustedbreaching tool. Thus, when the parts are assembled and the ball-cagemembers I5 are keyed to the sleeve as shown, onehalf the number ofstraight portions I3 of the ball-race will be in register respectivelywith the bearing surfaces I8 of the sleeve, and the remaining straightportions and all or substantially all of each curved portion I4 of theballrace will lie in spaces 2B defined by the arched portions I9 of thesleeve and radial planes (denoted by the broken lines 20') passingthrough the ends of said arched portions. The result of this is that theballs in one-half of the number of straight portions of the ball-raceand in all or substantially all of each curved end portion thereof willnot have bearing contact with the shaft and sleeve and will therefore befree to move in either direction as impelled by the balls in the otherstraight portions of the ballrace. It is unnecessary that the archedportions of the sleeve shall be curvilinear in crosssection as shown atI9 in Fig. 1, or that the boundaries between these arched portions andbearing portions of the sleeve shall appear sharp and distinct as shownin that figure. Fig. '7, for example, illustrates a pointed archformation having plane surfaces 2l which may be said to blendimperceptibly into the narrow bearing surfaces 22gof that figure, sincethese surfaces 22 are merely extensions of the plane surfaces 2i andhence, for the purpose served by my invention, the surfaces 2| betweenthe radial planes denoted by the lines 20 are deemed to constitutearched portions of the inner face of the sleeve.

In Figs. 3 and 4, the ball-cage is slotted to form a plurality of (hereshown as four) closed ovalshaped, that is, oblong ball-races each havingtwo substantially straight axially disposed portions I3 and two curvedend portions i4 connecting the straight portions at eachv end thereofAnd, as in the case of the embodiment shown in Figs. 1 and 2, one-halfthe numbery of straight portions of the races are inregister,respectivelyewith the bearing surfaces i8 of the inner face ofthe sleeve H, while the other straight portions and all or substantiallyall of each curved end portion of the races lie within spaces 2@ definedby the arched portions I9 of the sleeve and radial planes (denoted asbefore by lines E) passing through the ends of said-arched portions. Theball-cage i may be held in proper operative relation to the sleeve bybeing leyed toene end of the sleeve as shown, the cut-out pieces 23thereof, which are produced by theslotting, being secured separately tothe sleeve in properupositions to form the several ball-races, by screws24.

Figs. 5 and 6 show howimyinvention may be applied to a shaft having flatfaces such as a rectangular shaft I. As applied to a rectangular shaftthe ball-cage may comprise fourmembers, such as fiat plates 25, oneforeach face of the shaft. As here shown, each of these members or platesis integral with a support or plate l5 secured to one end ofthe sleevei; and if desired their adjacent edges may be connected together to forma single hollow boX-likestructure. They are each slotted to form anovalshaped or oblong ball-race which is substantially filled with balls;and the cut-out pieces 23y are secured to the sleeve as by screws 24.The balls in one of the substantially straight portions of each racehave bearing contact with the shaft and the sleeve, while those in theother-straight portions and in all or substantially all of each curvedportion of each race are out of 'bearing contact and are therefore freeto travel in either direction as impelled by those balls which are inbearing contact; and as shown in Fig. 5, the balls preferably bear uponthe shaft along and near two diagonally opposite edges thereof andtherefore tend to hold the shaft yfrom rotation `relative in Fig. 5which is provided withrball-races in the manner shown in this figure,`would be equally The interior face of the3sleeve applicable to arounded shaft as vvellvasV to a rectangular shaft.

If the straight portions of the ball-races in any of the foregoingembodiments of my improvements are precisely parallel to the axis of theshaft in each case as shown in Figs. 1-6 inclusive, there will be atendency resulting from the constant use of the bearing to wear groovesin the shaft along the bearing surfaces traversed by the balls; and thisin turn may loosen up the bearing and destroy the exact fitting of theballs therein and eventually prevent the bearing fromgoperatingsmoothly.V To obviate this, -the-ballraces may be constructed so thatthe balls in bearing contactwith the shaft will not all traverse thebearing surface of the shaft in the same straight line. This may beaccomplished in either one of the two ways which I have illustrated inFigs. 8 and 9 which are developments respectively of the ballcircuitsshown in Figs. 2 and 4 with the following, changes. In Fig. 8 thestraight portions I3 of the ball-race are inclined slightly from anaxial direction. In Fig. 9 the straight portions I3 are slightly curvedso that Yin this case the ball-races comprisecurved longitudinalportions and curved transverse portions connecting the ends of thelongitudinal portions. By either inclining the straight longitudinalportions from an axial direction or curving them, in `any bearing ofthis type, it will be readily seen that the balls in bearing contactwith the shaft will not traverse the same straightl line .along thebearing surface of the shaft and will thus obviate the tendency to weargrooves in the shaft and `thus will preserve smooth operation of thebearing indefinitely.

I claim as my invention:

1. A ball-bearing for shafts comprising a sleeve, Va ball-cage withinthe .sleeve .having a single continuous ball-race consisting of an evennumber of axially disposed substantially straight portions and a likenumber,Y of curved end portions connecting .the ends of the straightportions, and balls substantially filling said race and characterized bythiszthat the inner face of the sleeve Vis formed from end vto end withone-half said number of bearing surfaces, which have arched portionsbetween them. likewise extending from end `to .end ofthesleeve,that,onehalf said number of said straight portions of the raceare in register respectively with said bearingrsurfaces of thesleeve,.and that vthe other straight portions of the race andsubstantially all of each curved portion thereof lie within spacesdefined by the arched portions, ofthesleeve and radial planes passingthrough the-respective ends `of said arched-portions.

2. The ball-bearing defined-in claim 1 in which the ball-cage comprisesAtwo members keyed respectively to the ends of-the` sleeve and havinglingers which extend into the sleeve to form a continuous ball-race.

3. A ball bearing for linear,motionqcomprising a sleeve, a ballretainerLwithin .said sleeve having axially-directed.straightslots to guideVvthe of said sleeve .to the other to provide bearing surfaces forthevballsunder. loadand with'relatively wide relieved portionsbetween-the raised; f portions and extending from one end of said sleeveto the other to provide clearance for the balls not under load.

4. A sliding anti-friction bearing for a shaft. comprising a, sleeve,means within the sleeve and with which the sleeve cooperates to form oneor more continuous ball-raceways having straight.

axially-directed portions and curved-end portions, and ballssubstantially filling said raceways but being under load in no more thanonehalf the number of straight portions of the raceways, the inner faceof the sleeve being formed with bearing surfaces for the balls underload, which surfaces extend from end to end of the sleeve, and witharched portions alternating with said bearing surfaces, and thecurved-end por- 15.4

tions of the raceways lying within the areas deilned by said archedportions.

JOHN B. THOMSON.

REFERENCES CITED The following references are of record in the le ofthis patent:

` UNITED STATES PATENTS 10 Number Name Date 2,452,117 Ferger Oct. 26,1948 FOREIGN PATENTS Number Country Date 755,957 France 1933

